The number of hosts you're connected with depends on how many nodes u've chosen to be connected to. On the window "connection", u can chose how many outgoing and incoming connections u wanna have.
Personnaly, i use to have 5 outgoing and 5 incoming connections (1 of them is average 500 "hosts" but can be more or less).


The amount of connections does affect the download rate, but unless u have a very slow connection, u can download 3 or 4 files at the same time, cause hosts are used to limit upload rate.

If u want ur download rate to be higher, select "cable/adsl" on "Min speed" from the "search" window.

Hope i helped!